Field of the Invention
The present disclosure relates to a thermal collector panel for collecting solar thermal energy and a module comprising a plurality of thermal collector panels, and more particularly, to a vacuum solar thermal collector module that may absorb solar thermal energy collected inside using a vacuum thermal collector panel made of glass efficiently at a minimum loss and convey it to a heating medium, in particular, a large-scaled solar thermal collector module comprising a plurality of vacuum thermal collector panels.
Description of the Related Art
Generally, as a method for using solar heat as an energy source, a method of using a solar cell which collects solar heat and generates electrical energy is widely known. As a method for using solar heat other than the foregoing-described method for using solar heat by converting to electrical energy, there are various types of thermal collection devices that may collect solar radiation efficiently and use it as a heating source directly or indirectly.
That is, through a method that allows a heating medium to absorb thermal energy through heat transfer after a thermal collector panel absorbs radiant light rays from the sun and flows the heated heating medium, hot water is produced and used for building cooling and heating and hot water supply, or utilized in industrial process heat, thermal electric power generation, and the like. A key of a technology for harnessing solar thermal energy is solar thermal collection, solar thermal storage, and system control, and because solar thermal energy has a low energy density and a big variation with seasons and time of the day, thermal collection and storage is a basic technology, and thus, various attempts for thermal collection and storage have been made.
FIG. 1 illustrates an example of a solar thermal collector panel according to a related art.
Referring to FIG. 1, the conventional solar thermal collector panel includes a metal case 1 in a shape with an open top and an internal space and a transmission glass window 2 covering the top of the metal case 1. The glass window is transparent and allows sunlight penetration therethrough to bring radiant energy from the sun into the solar thermal collector panel. Inside the thermal collector panel, an insulation 3 and a thermal collector plate 4 are stacked on the metal case 1 in a sequential order. The thermal collector plate 4 is where solar thermal energy entering through the transmission glass window 2 is collected, and uses a suitable material for heat collection. The insulation 3 is provided between the thermal collector plate and the metal case to block heat to prevent heat transfer therebetween.
Also, a thermal absorber plate joined with a heating medium pipe 5 through which a heating medium flows is disposed between the thermal collector plate and the insulation. Solar thermal energy collected in the thermal absorber plate 4 is conveyed to the heating medium flowing in the heating medium pipe 5 and stored in a heat storage device through a heat exchanger.
However, the conventional solar thermal collector panel has a problem with a failure to convey solar thermal energy to a heating medium effectively and a loss of solar thermal energy.
That is, a loss of energy (a) caused by reflection on the surface of the transmission glass window occurs, and heat reflected off the surface of the thermal collector plate or heat absorbed in the thermal collector plate experiences a loss of energy (b) caused by convection of an air layer itself inside where the thermal collector plate 4 is mounted. In this instance, a very large loss of energy, to be concrete, an amount of loss of energy (b) equivalent to about 23% of the total incoming solar thermal energy occurs due to the presence of the air layer inside the thermal collector panel.
Also, because the insulation 3 cannot perform a perfect insulation function, a loss of energy (c) occurs due to leaks of thermal energy collected by the thermal collector plate 4 though the insulation 3 and the metal case 1 by conduction.
Also, conventionally, there is a solar thermal collector product with a vacuum inside, but a large amount of heat generates from surfaces of glass flat plates mounted at the top and bottom of a vacuum thermal collector, as a result, the upper and lower glasses of the thermal collector are prone to stress due to a temperature difference, and when the glasses are damaged, the overall thermal collector needs to be replaced, unfortunately, damage to a certain part results in a loss of overall function.
Also, due to a vacuum inside, a thick front surface transmission glass window is used to resist an atmospheric pressure load against the internal vacuum, and for this reason, there are disadvantages of a heavy weight, high material costs, and an increase in absorption loss of the front surface transmission glass window itself.